1. Field of the Invention
The present invention relates to an interlocking mechanism for a camera and, in particular, to a camera interlocking mechanism for interlocking an extending or collapsing operation of a lens barrel with adjustment of visual field angle of a finder or adjustment of irradiation angle of a strobe.
2. Related Background Art
Recently under development are small-sized cameras which have excellent portability. Among these is a camera in which a lens barrel for forming an image of an object onto a film is adapted to be accommodated within the main body of the camera. Namely, there has been known a camera in which the lens barrel is completely accommodated within the main body when the camera is not in use but can be extended as a button or the like is manipulated when the camera is in use, and can further be extended to a large extent upon telephoto photographing. In such a camera, it is necessary to appropriately adjust the visual field angle of its finder and the irradiation angle of its strobe as the lens barrel is extended and collapsed (retracted after being extended). To this end, incorporated within the camera is an interlocking mechanism for moving a lens of its finder and the flash bulb of its strobe in synchronization with the extending and collapsing of the lens barrel.
The above-mentioned camera, however, has drawbacks in that a large space is needed for installing the finder, strobe, or interlocking mechanism, whereby the size of the camera may not efficiently be reduced. Namely, in this camera, it is unnecessary to adjust the visual field angle of the finder and the irradiation angle of the strobe during the time when the lens barrel moves from its accommodating position within the main body to a photographing position. Nevertheless, when the finder lens and strobe flash bulb are completely interlocked with the extending and collapsing operation of the lens barrel via the interlocking mechanism, the lens and flash bulb would move more than necessary, thus increasing the space for installing the finder and strobe, whereby the size of the camera may not efficiently be reduced.
On the other hand, there is a case where a cam is used in the interlocking mechanism in order to restrain the finder lens and strobe flash tube from moving in the above-mentioned manner. For example, Japanese Patent Publication No. 4-78974 discloses an interlocking mechanism comprising a cam plate which moves to-and-fro in synchronization with extending and collapsing of a lens barrel, in which a cam groove is formed in the cam plate obliquely with respect to its moving directions, while the lens of the finder lens and the light-emitting bulb (flash bulb) of the strobe engage with the cam groove. In such an interlocking mechanism, the cam plate moves in synchronization with extending and collapsing of the lens barrel, and the finder lens and the strobe flash bulb move as the cam plate moves. As a part of the cam groove is formed in parallel with the moving directions of the cam plate, the finder lens and the strobe flash bulb can be restrained from moving more than necessary. In such an interlocking mechanism, however, the cam groove has to be made longer than usual, thus increasing the size of the cam plate. Consequently, the interlocking mechanism has a larger size, thereby becoming an obstacle to reducing the size of the camera.